/Engine/Plugins/Importers/USDImporter/Source/USDUtilities/Public/USDConversionUtils.h
Returns a modified version of InIdentifier that can be used as a USD prim or property name. This means only allowing letters, numbers and the underscore character. All others are replaced with underscores. Additionally, the first character cannot be a number. Note that this obviously doesn't check for a potential name collision.
namespace UsdUtils { [FString](API\Runtime\Core\Containers\FString) UsdUtils::SanitizeUsdIdentifier ( const TCHAR * InIdentifier ) }